lisa stark joins us from washington. what is the latest? >> that train should have been going at 30 miles an hour around the curve. there are no published reports this morning including from wabc, those reports indicate that the engineer, william rockefeller has said he may have zoned out at the controls. he may have dosed off and then snapped awake too late to stop the train in time the ntsb will continue to interview the engineer and also look back at [[voiceover]] no doubt about it, innovation changes our lives. opening doors ... opening possibilities. taking the impossible from lab ... to life. on techknow, our scientists bring you a sneak-peak of the future, and take you behind the scenes at our evolving world. techknow - ideas, invention, life. >> today's data dive gets preveny to examine the difference in gray matter between men and women. women have long claimed guys don't use their brains. turns out they may be half right. a university of pennsylvania study used brain imaging to look at brain cells at about 958 people. they found m